The purpose of this contract is to provide support services for the Viral Epidemiology Branch (VEB), Epidemiology and Biostatistics Program (EBP), Division of Cancer Etiology (DCE), National Cancer Institute (NCI) by conducting epidemiologic and natural history studies of hemophiliacs (and persons with related disorders) and their sexual partners and family members; by the maintenance, acquisition and use of epidemiologic data bases; by providing support for collecting and handling biologic specimens and laboratory data; and by statistical analysis of the data.